Bluetooth and other radio electronic keys has existed for many years and provided a convenient way to communicate identity at medium ranges, such as one hundred feet. However, Bluetooth and similar radio technology requires a power source, requiring the replacement and disposing of batteries or the replacement of the entire Bluetooth unit once the power cells are depleted.
Conversely, in passive radio frequency identification (RFID) based keys, a device is positioned within a close range in order for a user to be identified by an RFID reader. In these systems, the RFID credential is a passive device, meaning that the passive device does not contain its own power source, generally, and the passive device inducts power using magnetic coupling from the RFID reader. This presents an advantage that allows RFID credentials to last for many years without needing an internal power source. The disadvantage of RFID based keys, however, is the relative close proximity needed to that of the RFID reader in order for the RFID based keys to receive induced power.
Furthermore, because RFID readers generally deliver small amounts of intermittent power, typically 2-4 Milliamps (mA) in practice, within a close proximity, RFID based keys are unsuitable for long range communication or communication that may require intensive computing power. RFID reader data communication is typically slow being limited to the industry frequencies of 125 kilohertz (kHz) or 13.56 Megahertz (MHz) ranges. These frequencies allow data rates from 1000 bits per second to 900,000 bits per second in optimal conditions. The data rates depend greatly on how the RFID based key is positioned, the magnetic influences of the surrounding environment, the temperature, the humidity, the human usage, the condition of the device antenna and on. These factors make RFID based keys a poor choice for data intensive applications.
Most organizations have deployed some form of RFID based building access system to serve as a replacement or to augment physical keys and locks. These RFID systems have become insecure with simple card cloning. These RFID systems have become inconvenient with the shift into smartphone culture. However, the cost to replace or upgrade RFID systems in order to provide greater security is so great that organizations continue using the existing RFID based building access system. A replacement or upgrade of a single door costs upwards of one thousand dollars. Replacing 125 kHz RFID card with a more secure 13.56 MHz RFID card does not eliminate the inconvenience of carrying an RFID card along with a smartphone, nor in many cases does the RFID card improve the security.
Practically, the transition of using traditional physical access control RFID cards to mobile devices cannot happen all at once. Organizations will have to opt for a mixed system of RFID and smartphones or smart devices. Consequently, traditional RFID readers will most likely remain in use for a period of time.
The present invention uses Bluetooth communication to communicate with a Bluetooth enabled door reader in order to send and receive credential information about a user. The credential information is then used by the physical access control system to determine if the door in proximity to the RFID reader is accessible by the user. The portable computing device of the present invention receives power by harvesting the RFID field of the RFID reader already installed on the physical access control system, thereby not needing a large power storage device. This process enables the deployment of Bluetooth door readers or upgrades to existing RFID readers throughout a building with systems that communicate over Bluetooth. Power harvesting of RFID fields can now occur at greater distances as well as Bluetooth communication. The portable computing device advantageously leverages power harvesting at greater distances than RFID communication and is able to communicate over Bluetooth frequencies. This provides a better experience to the user who can identify himself or herself with the portable computing device at longer distances without having to replace batteries as that of existing devices that utilize portable Bluetooth systems.
Furthermore, the introduction of Bluetooth in these physical credentials provides a logical bridge with mobile device credentials by allowing a mobile device which contains an NFC reader to power the invention and allow the communication over Bluetooth to the invention for the transfer of information such as the updating of access credentials and encryption information.